Overweight or obese patients discharged from hospital after being treated for a serious infectious disease are about twice as likely to survive compared to those who have normal weight, new research shows.
The counter-intuitive finding – which appears to support a controversial phenomenon known as the obesity paradox – was based on a study of patients in Denmark.
A team led by Sigrid Gribsholt of Aarhus University Hospital studied more than 18,000 patients who had been admitted to a hospital in central Denmark with acute conditions related to infectious disease.
Overweight or obese patients discharged from hospital after being treated for a serious infectious disease are about twice as likely to survive compared to those who have normal weight, new research shows
They examined the risk of death within 90 days after discharge in three groups – underweight, overweight and obese patients. A group of normal weight patients served as a comparison group.
Key finding: obese and overweight patients do better
A key finding was that overweight patients were 40% less likely to die and those who were obese 50% less likely to die than those of normal weight.
‘Overweight and obesity were associated with substantially reduced 90 day mortality following incident hospital admission for infection,’ the authors concluded in an abstract of their study presented at this year’s European Congress on Obesity in Vienna, Austria.
The obesity paradox is controversial but past research provides some evidence for it.
A key finding was that overweight patients were 40% less likely to die and those who were obese 50% less likely to die than those of normal weight
Counter-intuitive finding is backed up by some evidence
For example, in people with heart failure those who would normally be considered to have an ideal weight die sooner than those who are obese. This may be because people tend to lose weight as they get progressively sicker – a situation that would favour overweight patients.
For patients suffering from an infectious disease like tuberculosis, which is associated with a sharp decline in body weight, heavier individuals may similarly have an advantage.
Obesity has also been associated with the release of a greater amount of anti-inflammation-related chemicals in the body. Thus, in the case of infectious disease, this might heighten the body’s defences and help fight against bacteria and viruses.
The evidence isn’t clearcut, though.
Confounding factors and controversy
A 2017 study of patients with community acquired pneumonia showed that patients’ mortality over six years was significantly lower in obese patients compared with normal-weight patients. But there was no significant evidence that inflammation was involved.
Those who disagree with the obesity paradox argue that other disease or lifestyle factors – such as smoking – may confound the results and show an advantage for obese patients where there really isn’t one.
That doesn’t appear to be the case in the Denmark study.
The researchers showed that among patients with obesity, presence or absence of recent weight changes, other health problems, cancer, or smoking had little effect on the association with decreased mortality.